Fixed issues #9, #10 and #12 as described on GitHub - HxCAS.

Change-Id: I9ce4833e9a9ab658ea91f07a724c20f6265a0114
Added VonNuemannGrid and corresponding tests.
Added VonNuemannGrid type to GridType.
Altered all existing world rules file extensions from .car to .cal.

Change-Id: Id1ac77ba3816c44dde4f77c9d8bc1dd02af3cd91
Altered code to allow for Von Neumann grids to be used.
Added VonNeumann3DWidget and VonNeumannWidget.

Change-Id: Id6578c768ddbc39d802b15da56f67d13eacca0e6
Altered code to allow for N-step engine. Normal worlds with singular
rulesets still work correctly.

Change-Id: Ib00956d0d6ee59c69127547b3da38537246d0dfb
Fixed minor bug.

Change-Id: Ie173f512e330ecc143fdfb969ca1103b7ce73464
Fixed minor bugs discovered during running of tests.

Change-Id: I4c97be2a0f91ae221a6e45ec0fc49df8ef19bc77
OPEN - task 17: Multiple statements in loop construct not working. 
http://github.com/Hexcore/HxCAS/issues/issue/17

Added test cases to replicate bug.
CLOSED - task 17: Multiple statements in loop construct not working. 
http://github.com/Hexcore/HxCAS/issues/issue/17

Fixed issue detailed above.
Merge branch 'bug_fix_cal_loop' into cos700_megan
Minor fixes and alterations.

Change-Id: I3d158e1e024b67456aaf791afb17c9717c3e88a6
Solved issue #19.

Change-Id: If66a60d9463b4ac1476b4954c34106c5643a44fa
Altered World and WorldReader.
World: Look for all rule set files numbered 1 upwards. Previously any
gap in numbering lead to un-loaded rule set files.
WorldReader: Removed redundant setting of default rule set when no
rule set is found.

Change-Id: I7e0c2923027986c7adb902936ac7bbe0839da876
Minor alteration to WorldReader when loading rule set files
(assumption: multiple rule sets world will always have numbered
rule set files and single rule set world will always be unnumbered).

Change-Id: I00c62eb81ae96dc18a1983909f504b4ca6bdcf2a
Removed old rule code calls.
Altered WorldReader and WorldSaver to work with new proposed storage
method of storing entire and difference generations - WorldStreamer
in process of being altered. Old storage type CAW files can still be
read but not saved.

Change-Id: Ib8f265733c110265d929eea29e6ae39f96c781eb
Fixed bug in GUI that resulted in Rectangle grids to become Von
Neumann grids.
Added Javadoc details to some classes.

Change-Id: I879b3b4f3501a23f8741d434d913734919df1e30
Added Javadoc information and minor alterations to deal with
ConcurrentModificationExceptions.

Change-Id: I7a4ed90581cf7e288a6a16df93c164ecebf0a038
Altered some Javadoc information.
Altered WorldStreamer to accommodate new storage method.
Minor fix to WorldReader.

Change-Id: I6ca51e3849e436ac09b167741c0eafb8b81fc3f2
Added @SuppressWarnings("unused") to length fields and TAG field.

Change-Id: I9e3a8228813c6c9b4f4e691fe75ae84db30d9574
Added missing logic to setRuleCodes function.

Change-Id: I0000000000000000000000000000000000000000
Fixed world streaming not comparing the correct generations.

Change-Id: Ifcc79a5b959fea53e010f8637e323a8df647b2d9